Regional Anatomy of the Pelvis and Perineum Flashcards
1
Q
Boundaries and anatomical relationships of subdivisions of pelvis & associated viscera
A
- Bony pelvis
- Innominate bones (ileum, ischium, pubis)
- Sacrum and coccyx
- Pelvic inlet
- From sacral promontory to pubic symphysis
- Pelvic outlet
- From pubic symphysis to coccyx
- Following ischiopubic ramus, ischial tuberosity, and sacrotuberous ligament
- False (greater) pelvis
- Superior to pelvic inlet
- Part of abdominal cavity
- True (lesser) pelvis
- From pelvic inlet to pelvic outlet (at pelvic diaphragm)
- Pelvic cavity (contains pelvic viscera)
- Pelvic walls consist of bone, ligaments (sacrospinous and sacrotuberous), and muscles (piriformis, obturator internus, with fascia)
- Pelvic floor consists of pelvic diaphragm (levator ani muscles, coccygeus muscles with superior and inferior fascia covering muscles)
2
Q
Pelvic diaphragm
A
- Levator ani muscle
- Coccygeus muscle
- Fascia:
- Superior
- Inferior
3
Q
Internal pelvic viscera: rectum
A
- Supported by and passes through muscular portion of pelvic diaphragm
- Diaphragm forms a sling, when contracted, aids external and internal anal sphincters in controlling defecation
- Pelvic diaphragm supports rectum and pelvic viscera
4
Q
Urogenital diaphragm
A
- Deep transverse perineus muscles in deep perineal pouch
- Superior fascia
- Inferior fascia (perineal membrane)
- Platform for the external genitalia
5
Q
Perineum
A
- Diamond shaped region between abducted thigh
- Inferior to pelvic diaphragm
6
Q
Anatomical relationships between uterus, ovaries, subdivisions of broad ligament
A
- Ovaries
- Produce eggs
- Endocrine organ
- Uterine (fallopian) tubes
- Fimbriae: collect ovulated egg
- Infundibulum
- Ampulla: normal site of fertilization
- Isthmus
- Uterus
- Fundus
- Body
- Cervix: projects into upper end of vagina
7
Q
Ligaments of female internal reproductive organs
A
- Broad ligament: peritoneal fold
- Mesovarium:
- Supports ovary and surrounds suspensory and ovarian ligaments and vessels
- Mesosalpinx:
- Surrounds and supports uterine tubes
- Mesometrium:
- Broad ligament inferior to mesosalpinx surrounding uterine vessels
- Mesovarium:
- Cardinal ligaments
- Located at base of mesometrium, extending from cervix to pelvic wall
8
Q
Testes
A
- Produce spermatozoa in seminiferous tubules
- Endocrine organ
- Rete testis
- Collecting chamber for spermatozoa
- Efferent ductules
- Connects rete testis with epididymis
9
Q
Epididymis
A
- Stores and functions in maturation of spermatozoa
- Head
- Body
- Tail
- Continuous with ductus deferens
10
Q
Ductus deferens & ejaculatory ducts
A
- Ductus deferens
- Muscular (smooth muscle) tube that transports spermatozoa from epididymis to ejaculatory ducts
- Ejaculatory ducts
- Combined ducts of ampulla (ductus deferens) and seminal vesicle
- Empties into prostatic urethra
11
Q
Seminal vesicles and prostate
A
- Seminal vesicle
- Contributes secretions to semen
- Prostate
- 30-40 individual glands
- Individual ducts drain into prostatic urethra
- Contributes secretions to semen
12
Q
Innervation of perineum
A
- Genitofemoral nerve
- Ilioinguinal nerve
- Pudendal nerve
- Posterior femoral cutaneous nerve
13
Q
Boundaries and contents of superficial and deep perineal pouches
A
- Superficial pouch
- From superficial perineal fascia (Colle’s fascia) to perineal membrane
- Encloses erectile tissues and their muscles
- Deep pouch
- From perineal membrane to superior fascia of urogenital diaphragm
- Encloses deep transverse perineus muscle and urethral sphincter (skeletal muscles)
14
Q
Areas of the pelvic bones most commonly fractured & clinical implications of the pubo-obturator fracture
A
- Pubic rami
- At risk during AP compression of pelvis (crush accident, heavy object fall)
- High risk of complication due to damage to urinary bladder and urethra
- Straddle injury (fracture of all 4 pubic rami) –> serious loss of pelvic stability
- Acetabulum
- At risk during fall on the feet from height
- Forces from ground drive head of femur into acetabulum
- Lateral compression of pelvis places acetabula and iliac blades at risk
15
Q
Most common injuries to the pelvic floor during childbirth
A
- Tearing injuries
- Grade 1 = superficial tissues
- Grade 2 = some tearing of muscles
- Grade 3 = tear extends to anal sphincter
- Grade 2+ tears most commonly pubococcygeous and puborectalis parts of levator ani
- Episiotomy (intentional cut) intends to decrease traumatic tearing of perineum
- Typically not performed anymore
- May be employed in cases of fetal distress, if descent of fetus becomes arrested, or when delivery with assistance of instruments is planned
